Our other Staffie, Chewie had terrible squits to start with eventually ending up on hypoallergenic expensive food after being found to be allergic to food storage mite. He'd keep getting flare ups so about 3 months ago both of them went on the RAW diet (vet recommended it), which is pretty gross but since then both have had good quality poo's and Chewie's coat has developed a glossiness it never had.

On a more serious note, any changes to diet are supposed to be introduced slowly. Switching to a 'BRAT' type diet to appease a dodgy tummy is likely as much to blame as the original cause surely? We made that mistake a few times.

Not that we feed our dog a BARF diet, but we get as close as we can afford to with her Biologically Appropriate dry food.. and stick to grain free (like the above mentioned Orijen is)
Any dog food that looks like a McDonalds take out, probably isn't the best choice you can make and likely lists grains as primary ingrediants then meat meal as opposed to having real meat based ingredients first.

This wesite below was a great resource for us when choosing dog food, along with specialist pet store advice from stores that dont and wont stock Purina type kibble..
I appreciate theres likely a significant cost implication with higher grade foods, however, often serving suggestions on teh pack reveal that far less high grade kibble is required to feed your dog, so a bag that requires 1/2 the serving size and is twice as expensive, effectively costs the same.

Dogs are often sensitive to certain things too. We tried a slow transition to Orijen 6 fish, but our mutt couldn't deal with it and she had the squits and unsettled stomach. Heavily fish loaded foods are a no go for her and we've settled on a mix of 2 grain free biologically appropriate kibbles (Now and Acana) as we couldn't justify the cost of the very highly rated Orijen products.

So, had a good poop last night so we tried some normal food with chicken for. Breakfast, squirty again. Put a bit of normal food with rice for lunch and he vomited. I'm guessing he's not a fan of bakers. What to move him on to or just to stick to chicken/rice for now?

You're right they will eat anything but when that anything starts ending up on your carpet 10 minutes after being eaten it makes it a little less easy to just say 'they'll eat anything'. Hope you don own a dog with that attitude!

Emma, seriously try toasted brown bread and boiled egg (with the chicken/rice). Don't rush it - it could take a while to get better. Stay well clear of Bakers - its made with stuff that banned in the EU for links to cancer!

One of our Springers used to have a bad stomach all the time as a pup. We put her on Arden Grange food and she has been fine since then. The vet recommended a fish flavour as it is gentler on their stomach than the meat ones so she is on the Salmon variety. Bakers is definately a food to avoid.